when i try to open through libreoffice a ppt/pptx file, it does not do so but libreoffice itself crashes.I am also unable to export it as pdf. I am managing by opening in google docs but with undependable net connections in my area, need to save on my desktop. I am very frustrated by this as i did not have it in openoffice or neooffice [mac version]

often the presentations have charts and maps in colour, but even text alone gives trouble
hope you can suggest some solution.